Conventional drawer slide construction generally includes a means to hold a closed drawer in position, such that the drawer does not unintentionally or inadvertently open, which could cause injury or damage. This is particularly important when drawer/cabinet structures are mobile, such as a cart, a tool box, a utility unit, furniture, etc. on wheels. Similarly, furniture, cabinets, toolboxes, racks, etc. which contain drawers supported by reciprocating slides may be placed on an uneven surface or floor. These situations could cause some tilt, sloping, or other conditions, whereby a drawer could inadvertently open by itself without any intentionally applied pull in the opening direction.
The conventional means to retain the drawer in the closed position, which is easily released when the drawer is pulled open, may be constituted, for example, by a frictional interface between an inner member of the slide (i.e., the drawer member) and a fixed rubber or polymer bumper located at the front or rear of the outer member of the slide (i.e., the cabinet member). These types of bumper designs are disclosed, for example, in U.S. Pat. No. 6,254,209 and U.S. Pat. No. 7,086,708.
These types of frictional fixed bumpers may work well when the drawer and cabinet structures are stationary or fixed in position, are on level ground, and are not mobile. Mobile applications, especially those with weight, such as tool boxes, or other rolling carts, tend to require selective detent holding forces to ensure that heavy loaded drawers remain closed when moved. One drawback of this is that, when the drawer is not heavily loaded, the high detent forces tend to require additional effort and/or cause other practical issues in opening and closing such a light-weight drawer.
An additional disadvantage of the frictional polymer detent interface is the consistency of the detent over time and use. Abrasion and wear of the interface (both in the opening and closing directions) tends to initially increase the pull force, then gradually subside as contact and wear may create a crease or groove in the rubber or polymer bumper. This, in turn, causes erosion and subtraction of material and contact interface from the mating interface component, which is generally a drawer member, without any means to adjust for this wear factor, and recapture the desired forces.